The next control in the basic toolkit is the menu. Menus are much like a series of nested buttons in the way you deal with them. Let’s create a simple menu. I’ve added a DockPanel, so we could nest our menu at the top, a very common scenario.

The underscore acts as an indicator to underline in the menu, designating a “hot key”. When the user hits the ALT key, they are then able to combine with the hot key to activate the menu option. ALT+F opens the File menu, O will then trigger the open.

Responding to the users click is just like working with many other controls, simply add a Click=”” in the MenuItem. Above you will notice I did this for one item, the Exit menu choice under File. Here’s the code I created in C#:

Since all the other menus work the same way I won’t bother to wire them up, but you get the idea.

It’s also possible to insert a separator, a visual line the separates one menu option from the rest. In this example, I think Exit should be separated from the other options.

And now we have a nice clean line across the menu:

OK, I can hear you now, “Hey, this is WPF, what about all the pretty pictures?” No problem, the menus support the addition of icons to each item.

One thing I’ve found many developers don’t realize is that Visual Studio actually ships with a nice array of graphics for your use. If you are using Visual Studio 2005, navigate to the C:\Program Files\Microsoft Visual Studio 8\Common7\VS2005ImageLibrary folder. There you will find a zip file named VS2005ImageLibrary.zip.

I extracted the icons folders to my D drive, as you’ll notice in the next code snippet. Adjust the sample according to where you decide to put them. I did find that on Vista, I needed to move them out of my Program Files folder or they didn’t render correctly, a security permissions issue.

For the MenuItems I wanted to add icons to, I need to define the MenuItem.Icon tag, then inside place an Image. The Source property I set to files I’d mentioned earlier. Note also I explicitly set the Height and Width to 16×16, in order to make them fit nicely into the menu. However, you are free to make them any size you wish, the menu item height will adjust automatically to compensate.

Ah, a work of art even Leonardo da Vinci would be proud of. But our artistic menus are not limited to the the top of the Window. It’s also possible to attach a menu to nearly any control, in the form of a ContextMenu. ContextMenus appear when you Right Click with the mouse on the control.

I’m adding a Grid to the body of the DockPanel. In the Grid I’m putting a TextBlock with some instructions, then a TextBox. Try right clicking on the TextBox, and take a look at what you get:

To get this to work, I first had to create a ContextMenu tag specific for the control, in this case TextBox.ContextMenu. Within that tag I was then able to place my ContextMenu. Inside it I treated it just like a normal Menu control, the code in there I simply copied from the other menus. I could even have the Click events route to the same code in the code behind module if I wished.

It’s worth pointing out that a menu may appear anywhere on the Window. Here I will create a menu to the right of the TextBox, in the next column of the Grid.

The menu code is the same as before, except I located in the Grid instead of at the top of the Window.

Virtually any application of decent size will need to employ a menu structure of some kind. Getting to know the basics of menu controls will get you ready for that first big WPF app.

Continuing the series on visual grouping controls in WPF, the Tab control is a common UI element that has been around for some time. It makes a convenient way to organize your window when there is more than could realistically fit and still be comprehensible.

In WPF, Tabs are very easy to implement. Create a new WPF Window, remove the default Grid tags, and add the following XAML:  

Run the app, and you’ll see the two tabs on a window:

The TabItem, just like most controls, can hold a container control that can hold much more, thus making the tab really useful. In this example, let’s add a third tab item, with a grid. We’ll put in a few text boxes and a button.

Using techniques already described in my post on Grids (https://arcanecode.wordpress.com/2007/08/28/grid-yourself-its-wpf/ , in case you missed it) I was able to create a tab with some useful content. Running it, you can see the results for yourself:

It’s also possible to determine the current tab via code. Let’s wire up a click event to that OK button you see. This requires we name the tab (I called it tabMyTabs), and the button, and add a Click=”CoolTabButton_Click” to the button declaration. Now all we have to do is add a little code:

Running and clicking on the OK button will result in a message box with the words “Tab Index=Cool Tab”

Granted my design won’t win any awards, but it gives you the general idea of how to use a tab control in WPF.

The other major listing control to cover is the ComboBox. It turns out that they are almost identical to ListBoxes. This simple code will add a combo box to your container (I’m using a StackPanel) and put two items into it.

Running will produce the predictable window with a drop down combo box and two items. If you want the user to be able to edit or enter his own text, you will need to set the IsEditable property to true and IsReadOnly to false in the <ComboBox> header.

Also like the ListBox, the ComboBox can contain complex items.

Note from the image above, if the contents of the drop down are too big it wil drop below the bottom of your current Window. Additionally, if you use automatic sizing the combo box will adjust itself rather oddly depending on the contents. For that reason, you may wish to set a default width rather than letting the combo box do it for you.

So how do we get data back out of the ComboBox? Well, if all we have is text, we can do just like we did with the ListBox, convert the selected item to a combo box item and get it’s Content.ToString property. But what if it’s like the above example, a mixture of text and images? Well we have to dig just a little, but it’s not that difficult if you understand the tree WPF creates.

Note I made two changes. First I added a name to the ComboBox, that way I can address it in code. Next I added a simple button control, we’ll use it to show what is currently selected. Just for the fun of it, I used the Content tag instead of placing it between the <Button></Button> tags, you may run across that form of syntax at some point and should be aware of it.

Now we need to add a little code to the myButton_Click event.

First, I got the current ComboBox item, and stored it in the cbi variable. I then check to see if it’s null, which it will be if the user hasn’t selected anything. If it is, we can show them the traditional “hey dummy” message, as I did in the else clause.

If you recall, the contents of the ComboBoxItem are a StackPanel control, so next I get a reference to it in the sp variable.

Next, I suppose I could iterate of the Children of the StackPanel, but since I know that the TextBlock I want is the first child, I’ll simply reference it directly as element zero and return it to the block variable.

Finally we can get to the actual text for the row the user picked. We can simply reference the TextBlock’s text property in the message box. When the app is run, you should see these results:

The same techniques I use here would also be applicable to the ListBox we’ve seen previously, simply replace ComboBoxItem with ListBoxItem.

The WPF ComboBox can be quite useful for providing a compact way for users to select complex items.